| abstract |
Process for dyeing keratinous fibres, in particular human keratinous fibres such as hair, characterized in that there is applied to these fibres a composition containing, in a suitable dyeing mixture, at least one indole-based coupler, of the formula: <IMAGE> (I) in which R1 designates a hydrogen atom or a C1-C4 alkyl radical; R2 and R3, which may be identical or different, designate a hydrogen atom, a C1-C4 lower alkyl radical, a carboxyl radical or an alkoxycarbonyl radical; X designates a hydrogen atom, a C1-C4 lower alkyl radical, a C1-C18 alkoxy radical, a halogen atom, a C2-C20 acyloxy radical or an acetylamino group; the OH group occupying the 6- or 7- positions of the aromatic ring; as well as the salts of these compounds; one oxidation dye precursor; one oxidising agent; the pH of the composition applied to the fibres being less than 7. |